Derivative Instruments (Effect Of Derivative Instruments On Consolidated Statements Of Operations) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Derivatives In Fair Value Hedging Relationships [Member]
Derivative [Line Items]
Gain (Loss) Recognized in Income on Derivative	$ 27	$ (6)
Gain (Loss) Recognized in Income on Hedged Item	(27)	6
Net Gain (Loss) Recognized in Income	(2)	(2)
Derivatives In Fair Value Hedging Relationships [Member] | Interest Rate Swaps [Member] | Net Gains (Losses) On Financial Instruments At Fair Value And Foreign Exchange [Member]
Derivative [Line Items]
Gain (Loss) Recognized in Income on Derivative	27	(6)
Gain (Loss) Recognized in Income on Hedged Item	(27)	6
Derivatives In Fair Value Hedging Relationships [Member] | Interest Rate Swaps [Member] | Interest Income (Expense) [Member]
Derivative [Line Items]
Net Gain (Loss) Recognized in Income	(2)	(2)
Derivatives Not Designated As Hedging Instruments [Member]
Derivative [Line Items]
Net Gain (Loss) Recognized in Income	334	(1,869)
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member] | Net Gains (Losses) On Financial Instruments At Fair Value And Foreign Exchange [Member]
Derivative [Line Items]
Net Gain (Loss) Recognized in Income	10	3
Derivatives Not Designated As Hedging Instruments [Member] | Currency Swaps [Member] | Net Gains (Losses) On Financial Instruments At Fair Value And Foreign Exchange [Member]
Derivative [Line Items]
Net Gain (Loss) Recognized in Income	(2)	(5)
Derivatives Not Designated As Hedging Instruments [Member] | Insured Credit Default Swaps [Member] | Unrealized Gains (Losses) On Insured Derivatives [Member]
Derivative [Line Items]
Net Gain (Loss) Recognized in Income	301	(1,411)
Derivatives Not Designated As Hedging Instruments [Member] | Insured Credit Default Swaps [Member] | Realized Gains (Losses) And Other Settlements On Insured Derivatives [Member]
Derivative [Line Items]
Net Gain (Loss) Recognized in Income	(4)	(354)
Derivatives Not Designated As Hedging Instruments [Member] | Non-Insured Credit Default Swaps [Member] | Net Gains (Losses) On Financial Instruments At Fair Value And Foreign Exchange [Member]
Derivative [Line Items]
Net Gain (Loss) Recognized in Income	(1)	(1)
Derivatives Not Designated As Hedging Instruments [Member] | Non-Insured Credit Default Swaps-VIE [Member] | Net Gains (Losses) On Financial Instruments At Fair Value And Foreign Exchange-VIE [Member]
Derivative [Line Items]
Net Gain (Loss) Recognized in Income	(1)	(158)
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps-VIE [Member] | Net Gains (Losses) On Financial Instruments At Fair Value And Foreign Exchange-VIE [Member]
Derivative [Line Items]
Net Gain (Loss) Recognized in Income	21	69
Derivatives Not Designated As Hedging Instruments [Member] | Currency Swaps-VIE [Member] | Net Gains (Losses) On Financial Instruments At Fair Value And Foreign Exchange-VIE [Member]
Derivative [Line Items]
Net Gain (Loss) Recognized in Income	(2)	2
Derivatives Not Designated As Hedging Instruments [Member] | All Other [Member] | Net Gains (Losses) On Financial Instruments At Fair Value And Foreign Exchange [Member]
Derivative [Line Items]
Net Gain (Loss) Recognized in Income	11	(1)
Derivatives Not Designated As Hedging Instruments [Member] | All Other [Member] | Unrealized Gains (Losses) On Insured Derivatives [Member]
Derivative [Line Items]
Net Gain (Loss) Recognized in Income	2	(11)
Derivatives Not Designated As Hedging Instruments [Member] | All Other-VIE [Member] | Net Gains (Losses) On Financial Instruments At Fair Value And Foreign Exchange-VIE [Member]
Derivative [Line Items]
Net Gain (Loss) Recognized in Income	$ (1)	$ (2)